Air separator and equalizer for dredges, including pump primer



March 12, 1957 Filed May 13. 1955 R. CARVER ET A AIR SEPARATOR ANDEQUALIZ L ER FOR DREDGES, INCLUDING PUMP PRIMER 2 Shedtm-Shpot I Royall5. Carver Leroy A Carver INVENTORS R. 's: CARVER ET AL 2,784,674AIR-SEPARATOR-AND EQUALIZER FOR DREDGES. mcwnmc; PUMP PRIMER March 12,1957 Filed May is. 1953 2 "Shoots-Sheet 2 Royall .S. Carver Leroy A.Carver 'INVENTORS United States Patent 0 AIR SEPARATOR AND EQUALIZER FORDREDGES, INCLUDING PUMP PRIMER Royall S. Carver and Leroy A. Carver,Washington, N. (1.

Application May 13, 1953, Serial No. 354,688

7 Claims. (Cl. 103-113) This invention relates in general toimprovements in dredging equiment, and more specifically to an airseparator and equalizer for dredges including a dredge pump primer.

Dredges engaged in dredging operations in streams and rivers and thelike have repeated shut-dowu periods due to the development of air locksin their centrifugal pumps. The air locks are due to the presence of airand gases of various types in the sand and muck which form the bottomsof the bodies of water being dredged. These air and gases mixed with thewater and solids are drawn into the centrifugal pumps of the dredgeswith the result that the air remains in the centrifugal pump and causesthe pump to be air bound. Not only does the presence of air within acentrifugal pump eventall'y cause the pump to be air bound, but theexistence of any air cuts down the efficiency of the centrifugal pump.

It is therefore the primary object of this invention to provide an airseparator unit adapted to be connected in the suction line of a dredgeintermediate the suction head and the centrifugal pump thereof forremoving substantially all air and gases from the dredged materialsprior to their passage into the pump so as to elimimate the possibilityof the pump being air bound.

Another object of this invention is to provide an improved air separatorfor hydraulic dredges, said air separator including an elongated chamberfor receiving all dredged materials passing into the centrifugal pump ofthe dredge, said chamber being provided with a least one air space inthe upper portion thereof for receiving air from the dredged materials,the air separator including air evacuation means connected to the airspace for withdrawing air under vacuum from the same.

Another object of this invention is to provide an improved air separatorand equalizer for dredges which is of a relatively simple constructionand which is rela' tively compact so as to be adapted for mounting inboth new and existing dredges.

A further object of this invention is to provide an equalizer forhydraulic dredges, said equalizer being in the form of an enlargedchamber disposed between the suction head and centrifugal pump of thedredge, the chamber being adapted to retain a quantity of water anddredged material so that the load imposed upon the centrifugal pump willremain substantially constant. regardless of fluctuations of the amountof solid dredged material being drawn into the suction head;

A still further object of this invention is to provide an improved airseparator and equalizer for dredges which is intended to remove air fromdredged materials through the use of a suction pump, the dredge being soarranged whereby the suction pump may be utilized to draw air out of thesuction lines and pump of the dredge and water into the same so as topermit ease of priming of the pump.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereice 2 inafter described and claimed,reference being had to the accompanying drawings forming a part hereof,wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a diagrammatic View of a hydraulic dredge pumping system andshows the air separator and equalizer which is the subject of thisinvention mounted therein;

Figure 2 is an enlarged front elevational. view of the air separator andequalizer and shows the general arrangement of the same, portions of theair separator and equalizer being broken away and shown in section inorder to clearly illustrate the construction of various parts thereof;

Figure 3 is a side elevational View of the air separator and equalizerof Figure 2, parts of the air separator and equalizer being broken awayand shown in section;

Figure 4 is an enlarged fragmentary elevational view showing therelationship of the float control valve and its associated float, theintermediate portion of the fioat being omitted and the valve beingbroken away and shown in section in order to illustrate the operatingparts thereof; and

Figure 5 is an enlarged fragmentary sectional View taken substantiallyupon the plane indicated by the section line 55 of Figure 2 and showsthe manner in which the float is guidingly mounted within an associatedtank to guide the vertical movement of the same.

Referring now' to the drawings in detail, it will be seen that there isillustrated in Figures 2 through 5, inclusive, the air separator andequalizer which is the subject of this invention, the air separator andequalizer being referred to in general by the reference numeral lit. Theair separator and equalizer it includes an elongated chamber which isreferred to in general by the reference numeral 12.

The chamber 12 includes a semi-circular cross-sectional bottom portion14 which terminates at its forward end in a pipe section 16 which isprovided at its forward end with a connecting flange 19. The rear of thebottom portion 14 terminates in a rearwardly extending pipe section 20which is provided at its rear with with a connecting flange 22.

The chamber 12 also includes a pair of upwardly diverging side walls 24and 26 whose upper edge is of a saw-tooth configuration. The chamber 12is completed by a front end wall 28', a rear end wall 3t) and a top wall32, the top wall 32 being provided with a vertical intermediate portion34.

Due to the saw-tooth configuration of the upper portions of the sidewalls 2'4 and 26 and the configuration of the top wall 32, the chamber12 is provided with a pair of air spaces 36 and 38, the air space 36being disposed forwardly of the air space 38. It will be understood thatdredged materials are to enter the chamber 12 through the pipe section16 and that air and gases contained therein will have a tendency to moveup into the air spaces 36 and 38 to permit separation thereof from thesolid and liquid dredged materials.

Secured to the forward portion of the top wall 32 and communicating withthe air space 36 is an enlarged vertically extending pipe section 4%.The pipe section 49 is disposed adjacent an enlarged tank which isreferred to in general by the reference numeral 42 and is connectedthereto by vertically spaced piping 44, the piping 44 being providedwith suitable connections 46 to permit the pipe 44) to be disconnectedfrom the tank 52.7 The tank 42 is suitably supported by standards 48 sothat the bottom wall 50 thereof is substantailly level with the top ofthe air space 36.

The tank 42, in addition to the bottom wall 50, includes a cylindricalbody portion 5'2 and a removable top wall 54. Mounted within the tank 42is an elongated float 56. The float 56 is in the form of a hollowcontainer and has depending guide members 58 secured to the lower endthereof. Vertical movement of the float 56 is guided by the guidemembers 58 being disposed within fixed guide elements 64 carried by thelower portion of the tank 42. The guide members 58 have their lower endsnormally in engagement with the bottom of the tank 42 to properlyposition the float 56.

Passing through the top wall 54 of the tank 42 in sealed relationtherewith is an outlet pipe 62. The outlet pipe 62 has secured to thelower end thereof a valve 64 which may be in the form of a generallyconventional globe valve. The globe valve 64 is modified to the extentthat its stem 66 has the threads removed therefrom so that the valve 64may be controlled by moving the stem 66 in and out of the valve body.The lower end of the stem 66 is connected to the top of the float 56 bya collar 68 so that the valve 64 will be controlled by vertical movementof the float 56. The valve 64 is also provided with an inlet 70 whichcommunicates with the interior of the upper portion of the tank 52.

Disposed adjacent the chamber 12 is a tank which is referred to ingeneral by the reference numeral 72. The tank 72 is provided at itslower ends with suitable supporting legs 7 and has passing through a topwall thereof a pipe 76. The pipe 76 depends a substantial distance witlin the interior of the tank 72 and has its opposite end connected to thepipe 62 by a pipe 78.

Also connected to the top wall of the tank 72 is a vacuum line 79 whichhas mounted therein a suitable vacuum gauge 80.

Referring now to Figure l in. particular, it will be seen that there isillustrated the dredging equipment of a conventional hydraulic dredge.The dredging equipment of a conventional hydraulic dredge includes acentrifugal pump 82 which has connected to its intake a suction line 84which terminates at its forward end in an intake or a suction head 86.The centrifugal pump 82 also has connected to its outlet, outlet piping88 so that the materials drawn in through the suction head 86 may bedistributed at the desired location.

It will be noted that mounted in the suction line 84 is the airseparator and equalizer 10. It will also be noted that the dredgingequipment includes a vacuum pump 90 which is connected to the vacuumline 79 and is intended to draw air from the air separator and equalizeri The vacuum produced on the vacuum line 79 is controlled by a suitablevalve 92.

Referring now to Figures 2 and 3 in particular, it will be seen thatwhen dredged materials are drawn into the chamber 12 through the use ofthe centrifugal pump 52, air and gases carried by dredged materials willescape upwardly into the air space 36. The air and gases passing intothe air space 36 will then pass into the tank 42 through the pipe 40. Inorder that air and gases trapped in the air space 38 may also pass intothe tank 42, there is provided a pipe 94 which connects the air space 38with the interior of the tank 42. It is pointed out at this time thatthe number of air spaces in addition to the air space 36 may varydepending upon the size of the dredge equipment. However, it will beunderstood that each additional air space 38 will be provided with apipe, such as the pipe 94, connecting it to the tank 42.

Inasmuch as the tank 42 is connected to the vacuum pump 9% through thevarious piping and the tank 72, it will be understood that there will bewater within the major portion of the tank 4-2, the height of the waterin the tank 42 being directly dependent upon the differential in vacuumbetween the suction line 84 and the vacuum line 79. When the water levelin the tank 42 is normal, the float 56 will remain at its lowermostposition and the valve 64 will be open. Thus, air passing into the tank42 and moving into the upper portion thereof will be drawn off into thetank 72 and thence, through the vacuum line 79, into the suction pump90. Any water and sand which is drawn into the tank 42 through the pipesand 94 which will increase the level of the water in the tank 42 will bepassed back into the chamber 12 through a sand return line 96 whichextends from the bottom of the tank 42 to the bottom portion 74 of thechamber 12.

It will be understood that a slight amount of water will be drawn intothe tank 72. The purpose of the tank 72 is to remove all water which maypass into the vacuum line 79. in order that the tank 72 may beperiodically drained, the same is provided with a suitable drain 98.

In the event that the suction in the vacuum line 79 should increase overthat in the suction line 84 to the extent that the water level in thetank 42 raises to the point where Water would enter into the valve 64,the float 56 will move upwardly, due to its increased buoyancy with theresultant closing of the valve 64. In this manner, the entrance of Waterdirectly into the pipe 62 is automatically prevented.

From the foregoing, it will be seen that there has been illustrated anddescribed a suitable air separation system which will remove air andgases from dredged materials passing into the suction head 86 of htedredge equipment. The removal of the air and gases from the dredgedmaterial prior to their entrance into the centrifugal pump 82 willprevent the centrifugal pump 82 from being air bound and thereforenecessitating the shutting down of dredging operations until such timeas the air may be bled therefrom and the pump reprimed.

In a normal dredging operation, especially when dredging a sandy bottom,the relationship of the solids to the liquids varies with occasionallysubstantially pure solids being drawn into the suction head 86. Thiscondition normally places an undue burden on the centrifugal pump 82which is not intended to accommodate over a certain percentage ofsolids. This is hard on a centrifugal pump, such as the centrifugal pump32, and causes undue wear on the pump as well as the possibility ofdamaging of drive machinery thereof. Inasmuch as the air separator andequalizer 10 includes the enlarged chamber 12 which is provided with areserve supply of water, including the water in the tank 42, it will beseen that should at any time there be an increased percentage of thesolids of the dredged material upon the entrance of such dredgedmaterials into the chamber 12, the additional water will mix with thedredged materials so as to equalize the load on the centrifugal pump 82.

Inasmuch as numerous types of solids and other material will pass intothe chamber 12, in order that the chamber 12 may be periodicallycleaned, the rear wall 30 thereof is provided with a suitable hand holewhich is closed by a hand hole cover plate 106. The hand hole coverplate 100 is removable, and facilitates the entrance of cleaning devicesinto the chamber 12.

When a dredging operation is to be started, it is necessary to firstprime the centrifugal pump 82. This re quires that water be drawn intothe suction line 84 and that all air be removed from both the suctionline 84 and the centrifugal pump 82. For this purpose, there is normallyprovided a small suction pump which is used to evacuate the air from thesuction line 84 and 82.

In order to eliminate the small suction pump mentioned above, the tank42 has connected thereto above the normal level of water therein asuction line 102 which is controlled by a valve 104. The suction line102 has its opposite end connected to the priming connection of thecentrifugal pump 82.

In order to facilitate the priming of the centrifugal pump 82, theoutlet line 88 is provided with a shut-ofl valve 106. When it is desiredto prime the pump 82, the suction pump 98 is actuated and the shut-offvalve 106 closed and the valve 104 opened. This will result in thedrawing of all air out of the suction line 84 and the pump 82 and thatportion of the outlet line 88 between the pump 82 and the shut-off valve106.

Inasmuch as the suction head 86 will be under water, the Withdrawal ofall air from the suction line 84 and the centrifugal pump 82 will resultin the drawing in of water into the suction line 84, the centrifugalpump 82 and the air separator and equalizer 10. After all air has beenremoved from the system, the valve 104 is closed and the valve 106opened with the simultaneous starting of the centrifugal pump 82. Thepump 82 being properly primed, the dredging equipment is now ready foroperation.

In view of the foregoing, it will be seen that there has beenillustrated and described a suitable attachment for dredges which may beutilized not only for the removal of air from dredged materials passinginto a centrifugal pump of the dredging equipment to prevent thecentrifugal pump from being air bound, but will also effectivelyequalize the load on the centrifugal pump and permit the priming of thesame without the use of an auxiliary suction pump.

From the foregoing, the construction and operation of the device will bereadily understood and further ex plan ation is believed to beunnecessary. However, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe in vention to the exact construction shown and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. An air separator for hydraulice dredges comprising an elongatedchamber having an inlet connectable to a suction head of a dredge and anoutlet connected to a 1 dredge pump, said chamber having an air space inthe upper portion thereof, air evacuating means connected to said airspace, separator means disposed between said air space and said airevacuating means for removing solids and liquid from air passing out ofsaid air space, said separator means including first and second tanks,said first tank being connected to said air space, said second tankbeing connected to said first tank and said air evacuating means, saidfirst tank being additionally connected to said chamber for retainingsolids and liquids thereto.

2. An air separator for hydraulic dredges comprising an elongatedchamber having an inlet connectable to a suction head of a dredge and anoutlet connected to a dredge pump, said chamber having an air space inthe upper portion thereof, air evacuating means connected to said airspace, separator means disposed between said air space and said airevacuating means for removing solids and liquid from air passing out ofsaid air space, said separator means including first and second tanks,said first tank being connected to said air space for primarilyreceiving air therefrom, said first tank being additionally connected tosaid chamber for returning solids and liquids thereto, said second tankbeing connected to said first tank and said air evacuating means, afloat controlled valve between said first and second tanks forcontrolling the direct flow of fluids between said first and secondtanks.

3. An air separator for hydraulic dredges comprising an elongatedchamber having an inlet connectable to a suction head of a dredge and anoutlet connected to a dredge pump, said chamber having an air space inthe upper portion thereof, air evacuating means connected to said airspace, separator means disposed between said air space and said airevacuating means for removing solids and liquids from air passing out ofsaid air space,

said separator means including first and second tanks, said first tankbeing connected to said air space, said second tank being connected tosaid first tank and said air evacuating means, a float controlled valvebetween said first and second tanks for controlling the direct flow offluids between said first and second tanks, said float controlled valvebeing actuated by a float mounted within said first tank.

4. An air separator for hydraulic dredges comprising an elongatedchamber having an inlet connectable to a suction head of a dredge and anoutlet connected to a dredge pump, said chamber having an air space inthe upper portion thereof, air evacuating means connected to said airspace, separator means disposed between said air space and said airevacuating means for removing solids and liquids from air passing out ofsaid air space, said separator means including first and second tanks,said first tank being connected to said air space, said second tankbeing connected to said first tank and said air evacuating means, saidfirst tank being normally partially filled with water, a priming lineconnected to said first tank below the normal water level thereof, saidpriming line being connected to the pump.

5. An air separator for hydraulic dredges comprising a horizontallyelongated vertically extending chamber having a lower inlet connectableto a suction head of a dredge and a lower outiet spaced longitudinallyfrom said inlet and connectable to a dredge pump, said chamber having anair space in the upper portion thereof, air evacuating means connectedto said air space, said chamber being relatively narrow and having amaximum width at its top, said chamber forming an equalizing chamber forthe flow of solids passing into the dredge pump to eliminateoverloading.

6. An air separator for hydraulic dredges comprising a horizontallyelongated vertically extending chamber having a lower inlet connectableto a suction head of a dredge and a lower outlet spaced longitudinallyfrom said inlet and connectable to a dredge pump, said chamber beingelongated in the direction of flow of water therethrough and having anair space in the upper portion thereof, said upper portion being of asaw tooth configuration to divide said air space into sections, and airevacuation means, piping connecting each of said sections to said airevacuation means.

7. An air separator for hydraulic dredges comprising a horizontallyelongated vertically extending chamber having a lower inlet connectableto a suction head of a dredge and a lower outlet spaced longitudinallyfrom said inlet and connectable to a dredge pump, said chamber having anair space in the upper portion thereof, air evacuating means connectedto said air space, said chamher being relatively narrow and having amaximum width at its top, said chamber forming an equalizing chamber forthe flow of solids passing into the dredge pump to eliminateoverloading, said upper portion being of a saw tooth configuration todivide said air space into sections.

References Cited in the file of this patent UNITED STATES PATENTS568,145 Sanderson Sept. 22, 1896 2,083,582 Taylor et a1 June 15, 19372,318,251 Moore May 4, 1943 2,666,671 Kimmerle Jan. 19, 1954 FOREIGNPATENTS 793,407 France Jan. 24, 1936

